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https://www.goodreads.com/book.../157641.Subway_Style
Somewhere in the ever-encroaching tide of railroad books I have "Subway Style" published by the NYC Transit Museum. It is a book that is an excellent and thorough history of all the publicly-visible station features. I will dig it out and see if they mention the 4th Avenue line, and if they have any photos or drawings. It might take a few days.
There are a few copies available on Amazon, for low prices. I recommend the book for anyone modeling or just interested in the subways of NYC.